From: Jim Baxter jim_baxter@mentor.com
[ Upstream commit aeca3a77b1e0ed06a095933b89c86aed007383eb ]
The zero padding that is added to NTB's does not zero the memory correctly. This is because the skb_put modifies the value of skb_out->len which results in the memset command not setting any memory to zero as (ctx->tx_max - skb_out->len) == 0.
I have resolved this by storing the size of the memory to be zeroed before the skb_put and using this in the memset call.
Signed-off-by: Jim Baxter jim_baxter@mentor.com Reviewed-by: Bjørn Mork bjorn@mork.no Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/net/usb/cdc_ncm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index dc6d3b0a0be8..feb61eaffe32 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -1118,6 +1118,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) u16 n = 0, index, ndplen; u8 ready2send = 0; u32 delayed_ndp_size; + size_t padding_count;
/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated * accordingly. Otherwise, we should check here. @@ -1274,11 +1275,13 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) * a ZLP after full sized NTBs. */ if (!(dev->driver_info->flags & FLAG_SEND_ZLP) && - skb_out->len > ctx->min_tx_pkt) - memset(skb_put(skb_out, ctx->tx_max - skb_out->len), 0, - ctx->tx_max - skb_out->len); - else if (skb_out->len < ctx->tx_max && (skb_out->len % dev->maxpacket) == 0) + skb_out->len > ctx->min_tx_pkt) { + padding_count = ctx->tx_max - skb_out->len; + memset(skb_put(skb_out, padding_count), 0, padding_count); + } else if (skb_out->len < ctx->tx_max && + (skb_out->len % dev->maxpacket) == 0) { *skb_put(skb_out, 1) = 0; /* force short packet */ + }
/* set final frame length */ nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;